You should watch her earliest concerts, from the 2001-2002 era. She used to do that all the time then, this strange inunciation of the last syllable so it sounds really funny. Since I am... was a song from that era, I suspect she relapsed into that style of singing.
Try watching Dome Tour, it was really really obvious then. An example, B&G.
The chorus, she modifies the last word "darou" into "dare".
2nd verse, the last words "teru" is modified into "tere".
But her mouth still forms the "u".
Just my take.
